docs: def _get_sa_at_1180(self, C, imt, sites, rup, dists):
          """
          Compute and return mean imt value for rock conditions
          (vs30 = 1100 m/s)
          """
          # reference vs30 = 1180 m/s
          vs30_1180 = np.ones_like(sites.vs30) * 1180.
          # reference shaking intensity = 0
          ref_iml = np.zeros_like(sites.vs30)
          # fake Z1.0 - Since negative it will be replaced by the default Z1.0
          # for the corresponding region
          fake_z1pt0 = np.ones_like(sites.vs30) * -1
          return (self._get_basic_term(C, rup, dists) +
                  self._get_faulting_style_term(C, rup) +
                  self._get_site_response_term(C, imt, vs30_1180, ref_iml) +
                  self._get_hanging_wall_term(C, dists, rup) +
                  self._get_top_of_rupture_depth_term(C, imt, rup) +
                  self._get_soil_depth_term(C, fake_z1pt0, vs30_1180) +
                  self._get_regional_term(C, imt, vs30_1180, dists.rrup)
                  )